import Pako from 'pako';

export interface EventData {
  data: string;
}

export class ResourceLoader {
  constructor(private document: Document) {}

  async load(type: 'analyzed' | 'sourceCode', filePath: string) {
    const rawSourceCode = new Promise<string>((resolve) => {
      const eventHandler = (event: Event) => {
        this.document.removeEventListener(`sabik:resourceLoaded:${type}`, eventHandler);
        resolve((<CustomEvent<EventData>>event).detail.data);
      };

      this.document.addEventListener(`sabik:resourceLoaded:${type}`, eventHandler);
      this.injectFile(filePath);
    });

    const data = new Uint8Array(
      atob(await rawSourceCode)
        .split('')
        .map((x) => x.charCodeAt(0))
    );

    return Pako.inflate(data, { to: 'string' });
  }

  private injectFile(filePath: string) {
    const script = this.document.createElement('script');
    script.setAttribute('src', `./event/${filePath}.js`);
    script.addEventListener('load', () => {
      script.remove();
    });

    this.document.body.appendChild(script);
  }
}